A concave lens is a type of lens that is thinner in the center than at the edges. It diverges light rays that pass through it, causing them to spread out. This property makes concave lenses useful in various applications, such as in eyeglasses for correcting nearsightedness and in cameras to control light. Concave lenses are typically made from glass or plastic and are shaped like a bowl, curving inward. They are often used in optical devices, including microscopes and telescopes, to help focus light and create clear images.